This invention relates generally to microtome and ultramicrotome mechanisms and more particularly to the specimen carrier arm thereof.
Microtome mechanisms are well known in the art. Such devices are described in: U.S. Pat. No. 4,317,401, issued on Mar. 2, 1982, to Disharoon and entitled, “Method and Apparatus for Microtomy”; U.S. Pat. No. 4,484,503, issued to Sitte et al. on Nov. 27, 1984, and entitled “Microtome having a Forward-Feed Control System for the Specimen Arm and/or the Knife”; U.S. Pat. No. 5,609,083, issued to Persson on Mar. 11, 1997, and entitled, “Method of and an Apparatus for Sectioning a Specimen”; and, U.S. Pat. No. 6,644,162, issued to Temple et al. on Nov. 11, 2003, and entitled “Microtome”; all of which are incorporated hereinto by reference.
Ultramicrotome mechanisms are also well known in the art and are used for slicing the specimens into finer slices. Such mechanisms are described in: U.S. Pat. No. 4,051,755, issued to Raveed on Oct. 4, 1977, and entitled, “Ultramicrotome and Attachment Therefore”; U.S. Pat. No. 5,181,443, issued to Sitte et al. on Jan. 26, 1993, and entitled, “Device for Controlling the Drive and Forward Feed of Microtomes, particularly Ultramicrotomes”; and, U.S. Pat. No. 5,226,335, issued to Sitte et al. on Jul. 13, 1993, and entitled, “Automatic Initial-Cutting Device for Microtomes, Particularly Ultramicrotomes”; all of which are incorporated hereinto by reference.
In general, there are two types of microtome mechanisms (and by extension, ultramicrotome mechanisms). The two types are differentiated by how the specimen slice is obtained through the performance of the specimen carrier arm.
In the first type of microtome mechanism, the specimen carrier arm is moved in a powered stroke. This is accomplished when a cam motor pulls or pushes the carrier arm (with specimen) through the knife. This assures that the arm cuts completely through the specimen in each rotation of the cam.
In the second type of microtome mechanism, the specimen arm is raised using the cam motor but is allowed to fall through the knife using gravity and the weight of the specimen arm. This type of mechanism allows a much “softer” type of cutting to be performed which is ideal for certain samples.
Often, a laboratory performing microtome operations is required to have both types of microtome mechanisms so that the needs of a particular sample can be effectively addressed. Obviously, this increases the equipment costs for the laboratory.
It is clear an economic advantage can be obtained if a single mechanism were to serve in both fashions.